Some ducted heating sounds are just metal expanding; others — persistent banging, rattling or grinding — point to a fault. Here’s what each noise means and when to have it checked.
Some NormalDucts expand & tick
Some NotBanging, grinding, rattling
Often FixableDucts, fan & service
Which Noises Are Normal?
Some ducted heating sounds are perfectly normal: the gentle rush of warm air through the vents, and ticking, popping or light banging from the metal ductwork expanding as it heats and contracting as it cools (often called ‘oil canning’). These expansion sounds typically happen at start-up and shut-down and are harmless. It’s the louder, harsher or persistent noises that indicate a problem.
Ductwork and Expansion
Much heating noise comes from the ducts. Expansion popping is normal, but loud or repeated banging can mean a duct section is poorly supported, has come loose, or is flexing excessively. Rattling often traces to a loose duct, grille or register vibrating. These are usually fixable by securing the ductwork and fixings. If the banging is loud and persistent rather than an occasional start-up pop, it’s worth having the ducts checked.
Fan and Unit Noises
Noises from the heating unit itself — humming, buzzing, rattling or harsher sounds — can come from the fan, motor or other components. A dirty or unbalanced fan becomes noisy; a loose panel rattles; a failing fan motor or bearing grinds or screeches. Many of these are addressed during a service. The harsher mechanical noises (grinding, screeching) are the ones to act on promptly.
Noises to Act On
Turn the system off and call a technician for grinding, screeching, loud repeated banging, or a harsh electrical buzz — these point to mechanical or electrical faults (fan motor, bearing, component) that can worsen and cause failure if the unit keeps running. A sudden change in the unit’s normal sound is also worth investigating. When in doubt, switching off and getting it checked is the cheaper path.
Getting It Fixed
A technician identifies the source — securing loose ductwork and fixings, cleaning and checking the fan, clearing debris, and inspecting components — and resolves it, often as part of a service. Where a component is failing, it’s repaired or replaced. Many noise complaints are simple fixes if caught early. A regular service keeps the system running quietly and catches developing issues. See our annual service guide.
Frequently Asked Questions
Why does my ducted heating make a banging noise?
A common, often harmless cause is ‘oil canning’ — the metal ductwork expanding and contracting (and popping) as it heats up and cools down, which makes a banging or ticking sound at start-up and shut-down. Louder or more persistent banging can indicate a duct problem or a component issue. If it’s an occasional pop as the system starts, it’s usually normal; loud, repeated banging is worth checking.
Is it normal for ducted heating to make noise?
Some noise is normal — the gentle rush of airflow, and ticking or popping from the metal ducts expanding and contracting with temperature. What’s not normal is persistent loud banging, rattling, grinding, screeching or a harsh electrical hum. Those point to ductwork, fan or component issues. So occasional expansion sounds are fine; new, loud or harsh noises warrant a look.
My ducted heating is rattling — what causes it?
Rattling is usually a loose component, panel or duct section vibrating, or debris in the system. It can also come from a loose grille or register. Most rattles are mechanical and fixable — tightening fixings, securing ductwork, or clearing debris, often as part of a service. It’s worth addressing so a minor rattle doesn’t develop into something worse, but it’s rarely an emergency.
My ducted heater is grinding or screeching — should I turn it off?
Yes — grinding or screeching usually points to a failing fan motor or bearing, and running the unit in that state can lead to failure and a bigger repair. Turn it off and have it checked. Unlike a harmless expansion tick, harsh mechanical noises are the ones that warrant stopping the system promptly and getting a technician to diagnose.
Can a service fix a noisy ducted heater?
Often yes — many noises (rattles, loose components, a noisy or dirty fan, debris) are resolved during a service that secures fixings, cleans and checks the fan, and inspects the ductwork. Where a component like a fan motor is failing, it’s repaired or replaced. Catching a noise early usually means a simpler fix, so it’s worth having an unusual or persistent noise checked.
Ducted Heating Problem or Service? Talk to FreshDuct
Service, repairs, carbon monoxide testing & replacement across Melbourne — 7 days a week. Call or request a quote.
